The New York Times did a profile on YouTuber Olga Kay who stars in 5 channels that collectively attract 1 million subscribers. She posts at least 20 videos per week. According to TubeMogul, a video ad-buying software company, the average CPM on pre-roll ads is $7.60. 2 out of every 10 views will have a video ad (this varies). The real CPM therefore is in the $1.50–$4 range.
Content creators say YouTube takes 45% of the ad revenue. If a video gets 300k visits on average per video, and the CPM is $2.50, the yearly earnings per video are $412.50 (before taxes). If someone creates 100 videos per year, the total earnings are $41,250 ($3437.50 per month). As long as your videos are being watched, YouTube income is passive after the video is posted. http://bit.ly/1ThdXm2